The present invention relates to a mounting structure for high pressure gas vessels and a mounting method and, more particularly, a mounting structure for high pressure gas vessels filled with high pressure fuel gas to be used as fuel in a fuel cell powered vehicle or the like and its related mounting method.
In recent years, a fuel cell powered vehicle which incorporates a fuel cell stack, as a power drive source, that generates electric power output upon electrochemical reaction between hydrogen and oxygen has heretofore been extensively focused as a vehicle to realize a reduced environmental pollution, and considerable research and development work has been currently undertaken toward the realization of such object.
There are some instances where pure hydrogen is selected as fuel of the fuel cell powered vehicle because of an extremely high total energy efficiency and less load to be affected in the environment.
Various structures have been studied to develop a particular structure for mounting a pure hydrogen vessel in the fuel cell powered vehicle, such as a structure composed of hydrogen occlusion alloy or a liquefied hydrogen tank. At current stages, one of the most realistic technologies to achieve such object is to provide a structure to allow high pressure hydrogen gas to be filled in a high pressure gas vessel to be installed in the fuel cell powered vehicle.
When filling high pressure hydrogen gas into the high pressure gas vessel to be mounted in the fuel cell powered vehicle and suitably mounting the high pressure gas vessel to a vehicle body while suitably plumbing connections of a high pressure conduit to be coupled to the high pressure gas vessel, it is an important theme for research and development work to be undertaken for allowing a hermetic sealing property to be enhanced in connecting portions between the high pressure gas vessel and the high pressure conduits and in joint portions among the high pressure conduits in a highly reliable manner.
Japanese Patent Application Laid-Open Publication No. H8-99542 discloses a plumbing technology, for pipe members within a vehicle, to permit a sub-frame structure composed of a fuel system and a high pressure piping system to be assembled in another sub-line prior to assembling the pipe members to the vehicle.
However, with such a structure, the plumbing operation tends to be adversely and strongly affected with various factors such as a vehicle body structure or a particular structure of the fuel system. As shown in FIG. 16, as the number of high pressure gas vessels 100, that specifically serve as fuel vessels to be mounted in the vehicle, increases, the pipe members P become complicated in structure and, also, an issue is encountered in plumbing shapes of the pipe members owing to a tolerance in design of and a variation in mounting positions of a fixing device and the fuel vessel that form the fuel system. As a result, special skills are required for extending the pipe members and for assembling these component parts. Further, the presence of increase in joint portions to be connected between the pipe members with respect to one another results in an increase in the number of joint portions which require particular hermetic sealing measures, causing an increased cost as well as an increased weight.
More particularly, when taking into consideration about a case where the high pressure gas vessel filled with high pressure hydrogen gas is mounted in the fuel cell powered vehicle, it is highly required for the high pressure pipe portions between the high pressure gas vessel and a pressure reducing valve to enhance a hermetic sealing effect.
In such a case, as shown in FIG. 17, it is possible for the study to be undertaken for providing a structure wherein the pressure reducing valve 101 is incorporated in the high pressure vessel 100 to deliver hydrogen gas, that is reduced in pressure, from an outlet of the high pressure gas vessel 100 to the fuel cell system. With such a structure, since the pipe member PO connected to the outlet side of the high pressure gas vessel 100 serves as a low pressure pipe, there is a reduction in the number of areas to which the hermetic sealing measures are to be undertake. Also, in the drawing, reference numeral 200 designates a charge port for high pressure gas and reference symbol PI designates a conduit connected between the charge port 200 and the high pressure gas vessel 100.
By the way, in the fuel cell powered vehicle, it is desired for high pressure hydrogen gas to be mounted in the vehicle by an amount as many as possible in order to enhance a tank mileage that can resists a practical use. Although it is thought that a technology to mount a large amount of high pressure gas in the vehicle is to use a largely sized high pressure gas vessel, it is fairly difficult to mount the large size high pressure gas vessel due to limitations in a layout of the vehicle. Thus, it is realistic to mount a plurality of relatively small size high pressure gas vessels.
In such a case, as shown in FIG. 18, if pressure reducing valves 101a, 101b are contained in the plurality of high pressure gas vessels 100a, 100b, respectively, either one of the pipe members POa, POb becomes the low pressure pipe, making it possible to take advantage of a reduction in the number of areas to which hermetic sealing measures are to be undertaken. With such a structure, however, it is considered that there is a variation in the amount of gas consumed in the high pressure gas vessels 100a, 100b owing to the variation in preset values in the pressure reducing valves 101a, 101b contained in the respective high pressure gas vessels 100a, 100b, and the use of the plural number of pressure reducing valves 101 causes a rise in cost and an increase in the weight.
To address this issue, as shown in FIG. 19, it is considered to be effective to employ a structure wherein the high pressure gas vessel 101a, containing therein the pressure reducing valve 101, and the high pressure gas vessel 101b containing no pressure reducing valve 101 are combined in use in a case where the fuel cell powered vehicle is mounted with the plurality of high pressure gas vessels.
With such a structure, however, the pipe member PObxe2x80x2, that interconnects the high pressure gas vessel 101a, containing therein the pressure reducing valve 101, and the high pressure gas vessel 101b with no pressure reducing valve 101 to one another serves as the high pressure pipe, with portions of the same being required to have a hermetic sealing effect.
The present invention has been made upon foregoing studies and has an object to provide a mounting structure and a mounting method for high pressure gas vessels wherein areas corresponding to high pressure pipes are reliably protected while precluding a stress strain from being generated at joined portions by precisely mounting the high pressure vessels for thereby enhancing a highly improved hermetic sealing effect.
To achieve the above object, according to one aspect of the present invention, there is provided a mounting structure for a plurality of high pressure gas vessels each of which has one end formed with a first neck portion, comprising: a block-shaped vessel mounting member allowing each of the plurality of high pressure gas vessels to be mounted; a plurality of accommodating portions located in the vessel mounting member, with each of the plurality of accommodating portions having a shape that corresponds to the first neck portion of corresponding one of the plurality of high pressure gas vessels and a base-valve mounted at the first neck portion so as to accommodate the first neck portion and the base-valve; and a gas flow passage located in the vessel mounting member to allow gas, contained in each of the plurality of high pressure gas vessels, to pass therethrough, the gas flow passage allowing the plurality of accommodating portions to communicate with one another while allowing the vessel mounting member to open at one side thereof and at the other side thereof. Each of the plurality of high pressure gas vessels is mounted to the vessel mounting member under a condition where the first neck portion and the base-valve, mounted at the first neck portion, are received in corresponding one of the plurality of accommodating portions located in the vessel mounting member.
In other words, a mounting structure, according to the present invention, for a plurality of high pressure gas vessels each of which has one end formed with a first neck portion, comprises: vessel mounting means for allowing each of the plurality of high pressure gas vessels to be mounted; accommodating means, which is located in the vessel mounting means, for accommodating the first neck portion and a base-valve mounted to the first neck portion, the accommodating means being associated with the plurality of high pressure gas vessels and having a shape that corresponds to the first neck portion and the base-valve mounted at the first neck portion of corresponding one of the plurality of high pressure gas vessels; and gas flow passage means, which is located in the vessel mounting means, for allowing gas, contained in each of the plurality of high pressure gas vessels, to pass therethrough, the gas flow passage means allowing the accommodating means to communicate with an outside of the vessel mounting means. Each of the plurality of high pressure gas vessels is mounted to the vessel mounting means under a condition where the first neck portion and the base-valve, mounted to the first neck portion, are received in the accommodating means located in the vessel mounting means.
On the other hand, according to the present invention, a method for mounting a plurality of high pressure gas vessels each of which has one end formed with a first neck portion, comprises: preparing a vessel mounting member which is formed with a plurality of accommodating portions and a gas flow passage, the plurality of accommodating portions being associated with the plurality of high pressure gas vessels, respectively, and each of the plurality of accommodating portions having a shape that corresponds to the first neck portion and the base-valve mounted at the first neck portion of corresponding one of the plurality of high pressure gas vessels, the gas flow passage allowing gas, contained in each of the plurality of high pressure gas vessels, to flow therethrough and allowing the plurality of accommodating portions to communicate with one another while opening at both one side and the other side of the vessel mounting member; accommodating the first neck portion of each of the plurality of high pressure gas vessels and the base-valve mounted at the neck portion in corresponding one of the plurality of accommodating portions formed in the vessel mounting member; and mounting each of the plurality of high pressure gas vessels in the vessel mounting member under a condition where the first neck portion and the base-valve, mounted to the first neck portion, are received in corresponding one of the plurality of accommodating portions located in the vessel mounting member.
Other and further features, advantages, and benefits of the present invention will become more apparent from the following description taken in conjunction with the following drawings.